You’ll need to enable the SteamOnlineSubsystem. You can do this by going to Edit → Plugins → Online and checking OnlineSubsystemSteam on.
Complete Setup:
DefaultEngine.ini:
[/Script/Engine.GameEngine]
!NetDriverDefinitions=ClearArray
+NetDriverDefinitions=(DefName="GameNetDriver",DriverClassName="/Script/OnlineSubsystemSteam.SteamNetDriver",DriverClassNameFallback="/Script/OnlineSubsystemUtils.IpNetDriver")
[OnlineSubsystem]
DefaultPlatformService=Steam
PollingIntervalInMs=20
[OnlineSubsystemSteam]
bEnabled=true
SteamDevAppId=480
GameServerQueryPort=27015
bRelaunchInSteam=false
GameVersion=1.0.0.0
bVACEnabled=1
bAllowP2PPacketRelay=true
P2PConnectionTimeout=90
[/Script/OnlineSubsystemSteam.SteamNetDriver]
NetConnectionClassName="/Script/OnlineSubsystemSteam.SteamNetConnection"
Secondly:
- In UE4, go to Edit->Plugins
- Select, Online Platform
- Enable, Online Subsystem Steam
- Restart Editor
If running a C++ Project:
Source ->GAMENAME->GAMENAME.Build.cs
Uncomment out the PrivateDependencyModuleNames.Add( ) line:
// Uncomment if you are using online features
// PrivateDependencyModuleNames.Add("OnlineSubsystem");